Chicago racetrack publicist Jack Doyle, former advertising man and amateur boxer, accepts the challenge of a new job in the world of thoroughbred horse racing—that of jockey’s agent. His client is a 17-year-old riding phenom from Ireland named Mickey Sheehan, who has decided to try her luck in the States. They prove to be an effective team until someone begins secretly administering dangerously illegal medications to horses, affecting race results. In his quest to identify the culprit, the shrewd, irreverent, and always opinionated Doyle is aided by his old friend Moe Kellman, furrier-to-the-Mob; trainer Ralph Tenuta, himself the target of a blackmailer; and young veterinarian Ingrid McGuire, a greatly talented horse communicator. Plus, Jack and Moe become co-owners of a talented, bargain-priced colt named Plotkin, who provides several thrills, not all of them welcome. The action moves from Chicago’s Heartland Downs to New York’s famed Saratoga Race Course, even stepping aboard Mob capo Fifi Bonadio’s lavish yacht in Chicago’s Belmont Harbor. Is that favor Jack agrees to do for Fifi going to get him killed, or will it be his persistent push for answers to the horse doping? Mickey’s sibling rivalry with her occasionally race-manipulating brother Kieran, one of Ireland’s top jockeys, comes to a climax with Mickey aboard Plotkin in the million dollar Heartland Downs Futurity, while Doyle pursues two daunting challenges to his colorful career as an amateur investigator in the world of American racing.